Camera and printing apparatus which can be used for trimming shots

ABSTRACT

A printing apparatus for preparing a print image out of a subject image formed by a photographic optical system and recorded on a recording medium comprises a unit for supplying data on the optical performances of the photographic optical system, a unit for setting a trimming magnification determining the trim range of the subject image recorded on the recording medium, a unit for setting the size of the print image, a unit for setting a maximum enlarging magnification for enlarging the subject image to a print image on the basis of the data read and the trimming magnification; and a unit for determining a final enlarging magnification for enlarging the subject image to a print image on the basis of the maximum enlarging magnification and the size of the print image.

This is a division of application Ser. No. 768,333 filed Sep. 30, 1991,which is a continuation of application Ser. No. 663,063 filed Feb. 28,1991 (abandoned), which is a continuation of application Ser. No.416,502 filed Oct. 3, 1989 (abandoned).

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a camera which is capable of recordinginformation designating a trimming range at the time of photographing.

2. Related Background Art

Cameras which can be used for trimming shots are already well known(see, for example, Japanese Patent Publication No. 61-43698). In atrimming shot, information designating the trimming range is recorded atthe time of photographing so that only the designated range of the imagetaken will be printed on photographic paper in the printing processafter the development of the film. Thus, what is obtained by printing isa trimmed picture representing a part of the shot image in an enlargedform.

Generally, the optical system of a camera photographic lens is sodesigned that its optical performance (including, for example, the MTF(modulation transfer function) and aberration) allow a satisfactoryimage to be obtained uniformly over the entire area of the shot image.However, as is generally known, optimum images of a subject are formedat different positions in the direction of the optical axis fordifferent heights of the image above the optical axis, so that theoptimum image field obtained by an image-forming luminous flux aroundthe optical axis generally differs from that obtained by a peripheralimage-forming luminous flux.

When, as in a trimming shot, only a portion of an image is to beprinted, image optimization presents a problem. More particularly,depending on the location of the image portion to be printed (forexample, an image portion whose height Y above the optical axis isapproximately 0 versus one whose height Y above the optical axis isapproximately 20 mm), there may or may not be a correspondence with theoptimum image portion in the overall photographic image.

In addition, when printing trimming-shot images, the enlargingmagnification is higher than in normal shots, where the entire shotimage is printed on photographic paper. As a result, the quality of atrimming-shot image is inevitably inferior to that of a normal-shotimage. Thus, a trimming shot is quite likely to fail to provide anoptimum image which would surely have been obtained by a normal shot,although better optical performance of the photographic lens is desiredtherefor.

The problems with the relevant prior art will be further discussed. Thephotographic apparatus disclosed in the above-mentioned reference,Japanese Patent Publication No. 61-43698, is equipped with a finderoptical system which makes it possible to set a trimming range incorrespondence with the visual field of the finder. A trimming-controlmeans which is coupled with the finder optical system drives atrimming-information recording device, thereby recording the trimmingmagnification corresponding to the visual field of the finder.

In the above-described prior art, the print enlarging magnification fora trimming shot is higher than that for a normal shot (the magnificationcorresponding to a standard print size, for example, the "servicesize"), so that a deterioration in the quality of the peripheral imageportions that would constitute no particular problem in a normal shotmay be conspicuous in a trimming shot.

The enlarging magnification designated is the same whether the trimmingis to be effected in the middle of an image or in a peripheral areathereof as long as the image size is the same. This is in particular aproblem where trimming is effected in a peripheral image area because asatisfactory image quality is often not obtained there. In order that asatisfactory image quality may be secured, it has been proposed that thelens aperture be controlled at the time of photographing. This, however,involves changes in the out-of-focus effect, so that the image asintended by the photographer cannot be obtained.

SUMMARY OF THE INVENTION

It is accordingly an object of this invention to provide a camera whoselens is driven and controlled in accordance with information on itsoptical performance and the trimming range, thereby improving the imagequality of a trimming shot.

Another object of this invention is to provide a camera which is capableof determining a maximum trimming magnification which allows images of asatisfactory quality to be obtained in accordance with information onthe optical performance of the lens, information on the opticalsensitivity of the recording medium, and information on thephotographing conditions such as the f-number.

Still another object of this invention is to provide a camera whichallows the photographer to set a desired trimming magnification, whichcan be recorded, along with the maximum trimming magnification thatallows images of a satisfactory quality to be obtained, on a recordingmedium (such as film) as trimming information.

A further object of this invention is to provide a printing apparatuswhich is adapted to read from the recording medium trimming information,which information includes the trimming magnification desired by thephotographer and the maximum trimming magnification, and to performtrimming in an appropriate manner.

To obtain the optimum image in a range, designated when taking atrimming shot, two methods now to be discussed may be adopted.

The first method entails moving the entire optical system incorrespondence with the curvature-of-field aberration. Of course themovement of the entire photographic-lens system in the direction of theoptical axis is limited to the range which can be regarded as in-focus.

FIG. 4A is an optical-performance chart showing the curvature-of-fieldaberration of a photographic lens at an in-focus position. It will beunderstood that, in the case of a normal shot, it is sufficient for theentire photographic-lens system to be moved in such a manner that theimage-sensing surface (film surface) is matched with position P2 of FIG.4A, since what is required here is that an optimum image is obtaineduniformly over the entire range of the photographic image.

In the case of a trimming shot, however, only a part of the photographedimage is printed in an enlarged form. Thus, when the range indicated bythe arrow A or B is designated for trimming, a print of noticeablyhigher resolution can be obtained when the entire photographic-lenssystem is moved in such a manner that the image-sensing surface ismatched with position P1 or P3, rather than with position P2.

The second method entails changing the MTF-curve itself. This can berealized by intentionally moving a certain part of the photographic-lenssystem in the direction of the optical axis. FIG. 4B is anoptical-performance chart showing MTF-curves C1, C2 and C3 of thephotographic-lens system. In the normal shot, a part of thephotographic-lens system is moved in the direction of the optical axisto make the MTF values at different heights of the image above axisapproximately equal to each other so that a satisfactory image asrepresented by C2 of FIG. 4B may be obtained uniformly over the entirepicture. Of course, this movement of a part of the photographic-lenssystem is limited to the range which can be regarded as in-focus.

In the trimming shot, the image is normally enlarged when printing ascompared to that obtained by the normal shot, so that the MTFperformance represented by curve C2 of FIG. 4B is not sufficient. Whenthe trim range is determined as indicated by the arrow C of FIG. 4B(where the height of the image above the axis is 0 to 5 mm), an optimumimage can be obtained by moving a part of the photographic-lens systemin the direction of the optical axis in such a manner that the MTF ishigh only in this range, that is, the MTF-performance becomes asrepresented by curve C3. When the trim range is determined as indicatedby the arrow D (where the height of the image above the axis is 15 to 20mm), an optimum image can be obtained by moving a part of thephotographic-lens system in such a manner that the MTF is high only inthis range, that is, the MTF-performance becomes as represented byMTF-curve C1.

In accordance with this invention, information on the correction of theoptical system of the photographic lens is compared with the trim rangedetermined by the photographer when performing a trimming shot and theoptical system is set in such a manner that the optimum opticalperformance can be obtained in the trim range. Accordingly, the optimumresolving power can be obtained in the trim range arbitrarily determinedwhen performing the trimming shot, thus making it possible to minimizethe deterioration in image quality due to the increase in the enlargingmagnification at the time of printing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a first embodiment of this invention;

FIGS. 2A to 2C are diagrams showing trim ranges for trimming shots;

FIG. 3 is a diagram illustrating a trim-range dividing pattern in thelens ROM;

FIG. 4A is a chart illustrating the relationship between the curvatureof field and the photographing range (the height of the image above theaxis);

FIG. 4B is an MTF chart showing changes in the MTF when a part of theoptical system is moved in the direction of the optical axis;

FIG. 5 is a block diagram showing a second embodiment of this invention;

FIG. 6 is a block diagram showing a third embodiment of this invention;

FIG. 7 is a block diagram showing a trimming camera in accordance with afourth embodiment of this invention;

FIG. 8 is an MTF chart of an optical system;

FIG. 9 is a diagram illustrating the enlarging amount; and

FIG. 10 is a block diagram showing a printing apparatus constituting afifth embodiment of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows an embodiment of this invention, in which the correction ofthe curvature of field is effected through the trim range, therebyimproving the image quality in the trim range.

A camera body 3 which is capable of trimming as well as normal shots isequipped with a mode-select switch 6 which makes it possible toarbitrarily switch between the normal-shot mode and the trimming-shotmode, as well as a trim-range setting device 7 which can be manipulatedon the outside so as to arbitrarily set the trim range. Here, a casewill be considered where the center O a full-size picture 19 is the sameas that of a trim range 13, as shown in FIG. 2A.

The camera body 3 includes a finder 12 which can indicate the trim-rangeframe 13. Provided inside the camera body are a trim-range changingmechanism 8 for changing the trim-range frame 13, a trim-range detectingmechanism 9 for detecting the trim range which has been set, atrim-range recording mechanism 10 for recording information on the trimrange on a film 11, and a CPU 5 for controlling the operation of thesemechanisms. The trim-range changing mechanism 8, the trim-rangedetecting mechanism 9, the trim-range recording mechanism 10, etc. arewell known in the art; they are disclosed, for example, in JapanesePatent Publication No. 61-43698, so an explanation of these mechanismswill be omitted here.

An interchangeable-lens barrel 2 is equipped with a photographic-lenssystem 1, an optical-system driving motor 18 adapted to drive thephotographic-lens system 1 in accordance with control signals from theCPU 5, and an ROM 14. The ROM 14 stores an optimum aberration-correctionamount for each of a plurality of trim ranges defined, as shown in FIG.3, in an expanding manner (in grades); from a smallest possiblequadrilateral to a full-size picture. When the interchangeable lens 2 isattached to the camera body 3, a mutual communication becomes possiblebetween the CPU 5, controlling the camera operation, and the ROM 14provided in the interchangeable lens 2.

The operation of this embodiment will now be described. The photographerselects the trimming-shot mode with the mode-select switch 6. Then, adesired trim range is set by means of the trim-range setting device 7while watching the picture frame 13 displayed on the finder 12 toindicate the trim range which is being selected. The picture frame 13 ismoved by a trim-range changing mechanism 8 in such a manner as toindicate a trim range which corresponds to the command input through thetrim-range setting device 7.

When the trim range has been determined, the positional information onthe range to be trimmed is transmitted to the CPU 5 by means of thetrim-range detecting mechanism 9. The trim ranges and theaberration-correction amount providing an optimum curvature of field foreach trim range are stored in order by trim range size (pos. 1 . . . n)in the ROM 14 provided in the lens. From the lens ROM data, the CPU 5 inthe body selects, on the basis of the positional information on the settrim range detected by the trim-range-detecting mechanism 9, the datablock of the aberration-correction amount for the trim range that isclosest to the set trim range. In FIG. 3, for example, the actually settrim range 13a, which is indicated by the broken line, is represented bythe trim range of pos. n - 1. Thus, the lens ROM data selected is thedata block of the curvature-of-field-correction amount which providesthe optimum resolving power in this trimming-shot range.

When performing a trimming shot, the entire lens system 1 isautomatically driven in the direction of the optical axis by the motor18, not in accordance with the aberration-correction amount set for anormal shot, but in conformity with the aberration correction amountnewly obtained as described above to match the set trim range.

Simultaneously with the photographing, the information on the trim rangeselected by the photographer is recorded on the film 11 by the recordingmechanism 10.

Embodiment 2

FIG. 5 shows a second embodiment of this invention. This is a method ofsetting the optical system in such a manner that an optimum MTF isobtained for the trim range.

The basic construction of this embodiment is the same as that of theembodiment shown in FIG. 1, so the same reference numerals are employedhere. In the second embodiment, the interchangeable lens 2 contains amotor 18 adapted to drive a certain part 1a of the photographic-lenssystem 1 in the direction of the optical axis. This motor 18 iscontrolled by the CPU 5 in the camera body 3.

Next, the operation of this embodiment will be described.

When the trimming-shot mode has been selected and the range 13 fortrimming has been determined, the positional information on the trimrange is detected by the trim-range detecting mechanism 9 and istransmitted to the CPU 5. The ROM 14 in the lens stores, as in the firstembodiment, trim ranges which are defined in an expanding fashion, asshown in FIG. 3, as well as position-setting data for the optical systempart 1a which provides an optimum MTF exclusively for each of the trimranges. The ROM 14 transmits these data to the CPU 5 in the body. Ofcourse, the arrangement is such that, at least in the range where focusdetection is performed (which is normally around the optical axis), animage which allows focus detection can be obtained. The CPU 5 selectsfrom the ROM data the MTF-data block for the trim range which is closestto the set trim range, and determines the amount of movement of theoptical system part 1a required for obtaining an optimum image in theset trim range.

On the basis of the results obtained through the above operations, thepart 1a of the photographic lens 1 is automatically driven by the motor18 provided in the lens. In this way, the optical system is set in sucha manner that an optimum resolving power is obtained in the range fortrimming, and the camera becomes ready for photographing.

In the above embodiments, the invention is applied to camera systemswhose photographic lenses are interchangeable. However, the applicationof this invention is not limited to such cases. It can be applied, forexample, to a camera having an integrally formed photographic lens, asin a compact camera, and the construction and operation of such a systemare basically the same as above.

As for the trim-range setting, the above-described method in which thetrim range is narrowed down toward the center of a full-size pictureframe (the center of the full-size picture frame is the same as that ofthe trim range) is mechanically simple and is generally preferred.However, the principles of the invention are equally applicable to asystem in which an arbitrary portion of a full-size picture for a normalshot is set as the trim range, as shown in FIG. 2B, or to a system inwhich the trim range is selected from among several preset trim ranges,as shown in FIG. 2C.

When the trim range is set in an arbitrary position as shown in FIG. 2B,a larger memory capacity will be required of the lens ROM, and the CPU 5will take a longer time in computing. In contrast, when the trim rangesare restricted to several preset patterns as shown in FIG. 2C, thecorrection amount for the curvature-of-field aberration (in the firstembodiment) or the amount of movement of the optical system part 1a forimproving the in-trim-range MTF (in the second embodiment) can be storedas data for each of these several patterns in the ROM 14. This helps toreduce the computation time for the CPU 5 and makes it possible to omitthe trim-range detect mechanism 9 and to use the trim-range settingdevice 7 only, thereby substantially reducing the time lag beforephotographing.

While in the above embodiments the curvature-of-field aberration iscorrected at the time of photographing in the trimming mode, thisinvention is not limited to this manner of correction. The photographiclens 1 may, for example, be driven in accordance with anaberration-correction amount in which other types of aberration aretaken into account along with the curvature of field.

As will be appreciated from the preceding description, in accordancewith this invention, an optical system is set to provide an optimumresolution in the range for trimming when taking a trimming shot, sothat, as compared to an image taken by an optical system which is setfor a normal shot only, the image quality can be improved as far as thetrim range is concerned. Further, the deterioration in image quality dueto the increase of the enlarging magnification at the time of printing,as has been characteristic of prior systems, can be precluded.

FIG. 8 shows MTF-curves indicative of lens optical properties. The linesA and B represent two different types of lenses, respectively. Thevertical axis indicates the MTF (modulation transfer function), and thehorizontal axis indicates the height of the image above the axis.Generally, the quality of an image obtained by a lens is, as will beappreciated from FIG. 8, inferior in the peripheral portions of theimage relative to the portion in the central section of the same, whichcorresponds to the optical axis. This is attributable to the fact thatlenses are designed attaching greater importance to the image quality inthe central section of the image since the main subject is generallyframed in the middle of the picture.

Referring additionally to FIG. 9, it will be appreciated that there is adistinct difference in image quality between the case where the trimrange is positioned between the image center and the height of say 10 mmabove the axis, as the trim range (a), and the case where the trim rangeis positioned between the heights of say 10 mm and 20 mm above the axis,as the trim range (b) (the trim ranges being assumed to be of equalsize). This difference is not so conspicuous when the enlargingmagnification (Z) (the magnification for enlarging the negative c to theprint size d) at the time of printing remains relatively small. However,as the magnification (Z) becomes larger, the difference becomes evident.Thus, when trimming a peripheral image portion, an upper limit must beestablished to the enlarging magnification (Z×Y) so that a satisfactoryimage quality can be secured.

Also in the case where the trim range is narrowed down toward the centerof the picture (the trimming magnification (Y) is increased), the upperlimit of the enlarging magnification (Z×Y) for printing and the MTF(contrast information) of the lens are correlated with each other.

Referring again to FIG. 8, the lens B indicated by the broken lineexhibits a more rapid fall of the MTF value than the lens A indicated bythe solid line.

Assuming that the trim range is set up to a height of 10 mm or so abovethe axis, the representation of the peripheral image obtained by thelens B will be inferior to that obtained by the lens A.

If pictures of an equivalent image quality are to be obtained by theselenses, the enlarging magnification for printing must be set lower forthe lens B.

If the same lens is used, the MTF is different for different aperturevalues and different object distances, the MTF value being better whenthe aperture is stopped down than when left open. By ascertaining theMTF values under different aperture values and object distances, theupper limit of the enlarging magnification, can be set more precisely.

Of course, the final enlarging magnification may be determined inaccordance with the information on aberration instead of the MTF value.

Apart from optical performance parameters related to aberration of whichthe MTF is typical, the images quality is influenced by the followingtwo factors:

(1) Factors related to focusing

For example, the depth of field is determined by the focal length, theobject distance, and the set aperture value. When photographing with asmall depth, a more accurate focusing is required. Since the enlargingmagnification is relatively high when photographing in the trimmingmode, any errors in focusing will appear more conspicuously at the timeof printing.

(2) Film sensitivity

As the sensitivity becomes higher, the granularity becomes more coarse.Assuming trimming is performed under the same conditions, a better imagequality is obtained when a film of a lower sensitivity is used.

Embodiment 3

FIG. 6 shows a third embodiment of this invention. A ROM 101 stores thelens MTF information (including information on aberration). Amagnification controller 102 is composed of amaximum-trimming-magnification setting part 102a and afinal-trimming-magnification setting part 102b, which serve to controlthe enlarging magnification. In the case of an interchangeable-lenscamera, the ROM 101 is arranged in the interchangeable lens and storesthe MTF information and the focal-length information which are peculiarto that lens, as well as the lens information used for automaticfocusing control. In the case of a lens-shutter-type camera, the ROM 101may be arranged in the camera body since in that case no interchange ofphotographic lenses is performed. The MTF information transmitted fromthe ROM 101 is input to the magnification controller 102. Photographinginformation including the film sensitivity (ISO) and the set aperturevalue (f-number) is input from an information output device 104 to themagnification controller 102. Further, other factors influencing theimage quality are input thereto from different determining devices inthe camera body.

A trimming-magnification setting device 105 includes an externaloperating member arranged on the camera body so as to enable thephotographer to arbitrarily set the trimming magnification (Y), andinformation indicative of the trimming magnification is input to themagnification controller 102 and to a printing-size setting device 106.

The printing-size setting device 106 includes an external operatingmember arranged on the camera body so as to enable the photographer toarbitrarily set a desired printing size. Information indicative of theenlarging magnification (Z×Y) showing the print size is input to themagnification controller 102 on the basis of the information from thetrimming-magnification setting device 105.

The maximum-trimming-magnification setting part 102a of themagnification controller 102 determines the maximum enlargingmagnification (X) which satisfies a standard image quality which ispreviously established on the basis of the input MTF information, thefilm sensitivity, the f-number, and the trimming-magnificationinformation.

When the trimming magnification (Y) and the print size have been set inthe camera, the enlarging magnification (Z×Y) is determined on the basisof the picture proportion.

The controller 102 compares the enlarging magnification (Z×Y) which isdetermined here with the maximum enlarging magnification (X). When themaximum enlarging magnification (X) is higher than the enlargingmagnification (Z×Y), the enlarging magnification (Z×Y) corresponding tothe print size set by the photographer is transmitted as the informationon the final enlarging magnification to a recorder 103, which recordsthis information on a film by an optical method. When the maximumenlarging magnification (X) is lower than the enlarging magnification(Z×Y), a satisfactory image quality cannot be obtained, so that an alarm107 controls the camera body such that no exposure operation can beperformed. The alarm 107 may warn the photographer through a signalsound or the like. Along with the warning thus given by the alarm 107,the maximum enlarging magnification at that time may be displayed.Instead of using the above-mentioned optical method, the recorder 103may record the information electrically on an EPROM or the like providedon the film cartridge, or magnetically on a magnetic tape or the like.

The information recorded by recorder 103 is utilized when developed theused film in the photofinishing laboratory, and is printed in a formenlarged with the optimum enlarging magnification.

It is also possible, even with a magnification below the maximumenlarging magnification, to rank the different image qualities obtainedthrough the enlarging magnifications of the print and to inform thephotographer of this ranking. For example, if the picture which is beingtaken is to be printed in the service size, it may be displayed to thephotographer as "Rank A", and, if it is to be printed in the cabinetsize or in the 10×12 inch size, as "Rank A" or "Rank B".

Embodiment 4

FIG. 7 shows a fourth embodiment of this invention. The construction ofthe fourth embodiment is substantially the same as the third, the onlydifference lying in the construction of the magnification controller 102and of the recorder 103. In the following, this difference will bedescribed.

The controller 102 compares the enlarging magnification (Z×Y) determinedby the printing-size setting device 106 with the maximum enlargingmagnification (X). When the maximum enlarging magnification (X) ishigher than the enlarging magnification (Z×Y), the enlargingmagnification (Z×Y) corresponding to the print size set by thephotographer is transmitted as the final enlarging-magnificationinformation to the recorder 103 through a signal line l1. The recorder103 then records the information on the film. The maximum enlargingmagnification (X) is also recorded through the signal line l2 asauxiliary information. When the maximum enlarging magnification is lowerthan the enlarging magnification (Z×Y), a satisfactory image qualitycannot be obtained, so that, in this case, the maximum enlargingmagnification (X) is transmitted as the final enlarging-magnificationinformation through the signal line l1 to the recorder 103, whichrecords this information on the film. Further, the enlargingmagnification (Z×Y) is also recorded through the signal line l2 asauxiliary information. In this case, the print size obtained in thephotofinishing laboratory is naturally smaller when enlarged with themaximum enlarging magnification.

The enlarging magnification thus recorded by the recorder 103, istransferred to the photofinishing laboratory along with the film used.In the photofinishing laboratory, magnification is determined on thebasis of the record from the recorder 103 when developing the used film,and printing is performed.

While in this embodiment, the ROM 101 and the controller 102 areseparate components, they may be replaced by a single CPU. Further, byproviding in the lens barrel or the camera body an encoder for readingthe position of the in-focus lens, the object distance can be judged.This arrangement makes it possible to read MTF information for eachobject distance, so that the maximum enlarging magnification can bedetermined more precisely. In a camera equipped with a zoom lens, anencoder for reading the position of the zoom-lens system may be furtherprovided, thereby making it possible to judge the object distance. TheMTF for the respective focal lengths and object distances can then betransmitted to the controller 102.

Embodiment 5

FIG. 10 shows a fifth embodiment of this invention, including a printingapparatus. Those components referred to by the same reference numeralsas in the third and fourth embodiments have the same construction as thecomponents previously described, so a description of them will beomitted.

A camera system (consisting of a camera body and a lens barrel) whichcan be used for trimming shots is equipped with an ROM 101 storing MTFinformation, an information-output device 104 adapted to outputinformation on film sensitivity and aperture values, and atrimming-magnification setting device 105 which allows a desiredtrimming magnification to be set through external operation. The datafrom the ROM 101, the information-output device 104 and thetrimming-magnification setting device 105 are, as described earlier,recorded by the recorder 103 on the film or on an EPROM on the filmcartridge. It is also possible, as in the embodiment shown in FIG. 7, tofurther provide in the camera system a printing-size setting device 106and a magnification controller 102. In that case, the informationrecorded will include an enlargement magnification corresponding to theprint size set by the photographer and the maximum enlargingmagnification as the main or auxiliary information.

In the printing apparatus, a reader 109 reads out, in the process ofdeveloping the film 108, information recorded on the film 108 or thefilm cartridge. The data read by the reader 109 is input to themagnification controller 102. A display device (not shown) displays thedata, distinguishing between the main information and the auxiliaryinformation. Unless the developer particularly wishes otherwise, themain information is recognized as the trimming magnification Y.

The printing apparatus is further equipped with a trimming-magnificationresetting device 150, which makes it possible to change the trimmingmagnification set by the trimming camera when printing. The trimmingmagnification is usually set by the trimming camera when photographing.However, when, for example, it is desired that the trimmingmagnification be reset after photographing, resetting can be effectedwhen printing by the trimming-magnification resetting device 150.

The magnification controller 102 is composed of amaximum-enlarging-magnification setting part 102a and afinal-enlarging-magnification setting part 102b, and serves to determinethe final enlarging magnification.

If the trimming magnification Y recorded in recorder 103, and thetrimming magnification Y' recorded in recorder 103 of thetrimming-magnification resetting device 150 are simultaneously input tothe reader 109, the reset trimming magnification Y' is adopted. Themaximum-trimming-magnification setting part 102a determines, in the samemanner as described above, the maximum enlarging magnification X fromother data recorded in the recorder 103 (i.e., data other than thetrimming magnification Y not used) and the trimming magnification Y'. Ifthe trimming magnification Y' is not set by the trimming-magnificationresetting device 150, the maximum-enlarging-magnification setting part102a naturally determines the maximum enlarging magnification X from thedata recorded in the recorder 103, including the magnification Y.

Further, either the trimming magnification Y or the trimmingmagnification Y' is input from the reader 109 to the printing-sizesetting device 106. When a desired print size is set by the user, theprinting-size setting device 106 sets the enlarging-magnificationinformation (Z×Y or Z×Y') on the basis of the input trimmingmagnification Y or Y'. This information is input to thefinal-trimming-magnification setting part 102b.

The final-trimming-magnification setting part 102b compares theenlarging magnification X determined by themaximum-enlarging-magnification setting part 102a with the enlargingmagnification (Z×Y or Z×Y') set by the printing-size setting device 106.When the maximum enlarging magnification X is higher than the enlargingmagnification (Z×Y or Z×Y'), the enlarging magnification correspondingto the set printing size is determined to be the final enlargingmagnification, as in the above-described embodiment. In the conversecase, the maximum enlarging magnification is determined to be the finalenlarging magnification.

On the basis of the final enlarging magnification determined by themagnification controller 102, the enlargement of the print is performed.When the final enlarging magnification is lower than the enlargingmagnification set by the printing-magnification setting device 106, asatisfactory image quality cannot be obtained, so that the alarm 107gives a warning through sound, light, etc.

Thus, in the fifth embodiment, the magnification controller 102 isarranged on the side of the printing apparatus, so that, even if thetrimming magnification is changed after photographing, the image qualitycan be ascertained before printing, thus making it possible to reducethe possibility of prints of an undesirable representativity beingyielded.

What is claimed is:
 1. A printing apparatus for preparing a print imageout of a subject image formed by a photographic optical system,comprising:a recording medium on which data includingoptical-performance data indicating the optical performances of saidphotographic optical system is recorded along with said subject image; areading means for reading said data recorded on said recording means; atrimming-magnification setting means for setting a trimmingmagnification determining the trim range of said subject image recordedon said recording medium; a printing-size setting means for setting thesize of said print image; a means for setting a maximum enlargingmagnification for enlarging the subject image to a print image on thebasis of said data read and said trimming magnification; and a means fordetermining a final enlarging magnification for enlarging the subjectimage to a print image on the basis of said maximum enlargingmagnification and the size of said print.
 2. A printing apparatus asclaimed in claim 1, further comprising a means for printing the subjectimage recorded on said recording medium in accordance with said finalenlarging magnification.
 3. A printing apparatus as claimed in claim 1,wherein said maximum enlarging magnification corresponds to a criticalenlarging magnification which allows an appropriate image quality of theprint prepared to be maintained.
 4. A printing apparatus as claimed inclaim 1, wherein the data recorded on said recording medium includesoptical information regarding the aberrations of said photographicoptical system and photographic information including the aperturevalues of said photographic optical system.
 5. A printing apparatus forpreparing a print image out of a subject image formed by a photographicoptical system and recorded on a recording medium, comprising:a meansfor supplying data on the optical performances of said photographicoptical system; a means for setting a trimming magnification determiningthe trim range of said subject image recorded on said recording medium;a means for setting the size of said print image; a means for setting amaximum enlarging magnification for enlarging the subject image to aprint image on the basis of said data read and said trimmingmagnification; and a means for determining a final enlargingmagnification for enlarging the subject image to a print image on thebasis of said maximum enlarging magnification and the size of said printimage.